The Bell X-14 (Bell Type 68) is an experimental VTOL aircraft flown in the United States in the 1950s. The main objective of the project was to demonstrate vectored thrust horizontal and vertical takeoff, hover, transition to forward flight, and vertical landing.
Bell constructed the X-14 as an open-cockpit, all-metal (duralumin) monoplane for the USAF. It was powered by two Armstrong Siddeley Viperturbojet engines equipped with thrust deflectors sited at the aircraft's centre of gravity. The engines are fixed in position; transition from vertical to horizontal flight is achieved with a system of movable vanes that control the direction of engine thrust.[1][2] Top speed was 180 miles per hour (290km/h) with a service ceiling of 20,000 feet (6,100m). The X-14 was designed using existing parts from two Beechcraft aircraft: wings, ailerons, and landing gear from a Beech Bonanza and the tail group from a Beech T-34 Mentor.[3]
Operational history
The X-14 first flew on 19 February 1957 as a vertical takeoff, hover, then vertical landing. The first transition from hover to horizontal flight occurred on 24 May 1958. In 1959, its Viper engines were replaced with General Electric J85 engines. That year the aircraft was delivered to the NASA Ames Research Center as the X-14A. During the development of the P.1127, Hawker test pilots Bill Bedford and Hugh Merewether visited NASA Ames to fly the X-14 and acquaint themselves with jet V/STOL aircraft handling prior to the first flights of the prototype P.1127.[3] It served as a test aircraft with NASA until 1981.
The X14 project provided a great deal of data on VTOL (Vertical Takeoff and Landing) aircraft and flight control systems, served as a vital training platform for the Apollo space program, and directly contributed to the development of the Hawker Harrier and later the Lockheed Martin F-35B.
In 1971, the X-14A was fitted with new engines (General Electric J85-GE-19) and redesigned the X-14B.[4][5] An onboard computer and digital fly-by-wire control system were also installed to enable emulation of landing characteristics of other VTOL aircraft.[citation needed]
The aircraft was used by NASA as a Moon-landing simulator.[6]Neil Armstrong flew the aircraft on numerous occasions. Armstrong himself described learning to hover in the X14 as being like “perching on a bubble of hot air.”[5]
The X-14B was used in this test role until it was damaged in a hard landing on 29 May 1981 and never repaired.[6] At the time, there were plans to develop an X-14C with an enclosed cockpit. There were also plans for an X-14T trainer. None of these further versions got beyond the planning stage.
During all of its years of service, the X-14 was flown by numerous pilots with no serious incidents or injuries.[5][6]
Aircraft N numbers
Although there was only one airframe and serial number, it changed N numbers from 234 to 704 when the airframe was upgraded under NASA.
1 2 Borchers, Paul F.; Franklin, James A.; Fletcher, Jay W. (1998). "Chapter 8, Boundary Layer Control, STOL, V/STOL Aircraft Research". (SP-3300) Flight Research at Ames, 1940-1997, Fifty-Seven Years of Development and Validation of Aeronautical Technology. NASA. pp.55–59. Retrieved 12 February 2013.
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